Smart Mutatable Advanced Technology Wheelchair · Simulation results obtained from RecurDyn have been used to analyze the rover capabilities and select the actuators for the rover

IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)

e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 10, Issue 6 Ver. II (Nov – Dec. 2015), PP 68-77

www.iosrjournals.org

DOI: 10.9790/1676-10626877 www.iosrjournals.org 68 | Page

Smart Mutatable Advanced Technology Wheelchair

Shruti Kulkarni1, Prashali Sharma

2, Nilay Chowdhury

3,

Tanay Chowdhury4 1(U.G Student, Electronics & Telecommunication, Pune University, Maharashtra, India)

2(U.G Student, Electronics & Telecommunication, Pune University, Maharashtra, India)

3(U.G Student, Electronics & Telecommunication, Pune University Maharashtra,, India)

4(U.G Student, Electronics & Telecommunication, Pune University, Maharashtra, India)

Abstract: While the needs of many individuals with disabilities can be satisfied with power wheelchairs, some

members of the disabled community find it difficult or impossible to operate a standard power wheelchair. To

accommodate this population, several researchers have used technologies originally developed for mobile

robots to create “smart wheelchairs” that reduce the physical, perceptual, and cognitive skills necessary to

operate a power wheelchair. We are developing a Smart Mutatable Advanced Technology wheelchair. This

paper describes the design of a prototype, which has been evaluated on wheelchair.

Keywords: disability, rehabilitation, smart features, smart phone, smart wheelchair.

I. Introduction The number of people who are paralyzed and therefore dependent on others due to loss of self-mobility

is growing with the population. The development of the wheelchair for paralyzed users is surprisingly recent

starting with the conventional manually powered wheelchairs and advancing to electrical wheelchairs.

Conventional wheelchair use tends to focus exclusively on manual use of hands which excludes those unable to

do so. Diseases or accidents injuring the nervous system also affect because people lose their ability to move

their voluntary muscle. Because voluntary muscle is the main actuator enabling people to move their body,

paralysis may cause a person not move their loco motor organ such as arm, leg and others.

Scientist Stephen W. Hawking is perhaps the most well-known victim of major paralysis – Hawking

was diagnosed with incurable Amyotrophic Lateral Sclerosis (ALS) in 1962, thereafter using a wheelchair to

move. Many of those suffering close to or complete paralysis usually however still can control their eye

movement which inspired us to develop an eye-controlled electric wheelchair.

(a) Alex Dev, Horizon C Chacko (2011) used EOG to control the wheelchair locomotion. A pair of

electrodes is placed horizontally to left and right Eye. If the eye is moved from the centre position

towards one electrode, a potential change occurs between the electrodes. Due to the changes in the

potential the wheelchair can be controlled.

(b) S.Tameemsultana and N. Kali Saranya (2011) [1] used head and finger movement for wheelchair

locomotion. In finger movement they use flex sensor, placed on the finger. It is an analog resistor usually in the

form of strip long variable resistance. Due to the bending of finger the resistance varies which controls the

locomotion of the wheelchair. Bending the sensor at one point more than 90 may permanently damage the

sensor which is a main drawback. The system already existing for the physically challenged person controlled

by other different technologies has some defects:

In Eye ball sensor they use infra red sensor to control the wheelchair where continuous fall of IR

radiation in the eye causes irritation to the patient (Alex Dev, Horizon C Chacko and Roshan Varghese,

April, 2012, ISBN.)

In voice control the person must use the exact commands only to control the movement. Change in the

words restricts the wheelchair movement (Manuel Mazo, 1995) [2]. All the electronic system and also

the philosophy for functioning has been sufficiently refined to attain the subsequent performances:

- To ensure easy, comfortable driving.

- To reply to the speed requirements for a system of this kind (maximum speeds of up to three m/s).

- To be simply adaptable to any kind of commercial wheelchair chassis.

- To ease learning to handle the chair and getting most potency.

- To ensure much constant speeds, to an oversized extent independently of the characteristics of the

surface over that the wheel chair is moving (greater or lesser roughness of the ground and also slope of

same) and the weight of the person using it.

Keeping in mind our aim of helping patients in all aspects, study was conducted to determine how to

collaborate easy functioning wheelchair with low cost. Hence a wheelchair was developed rounding off all

possible considerations to get a complete package of simple design, low cost and user friendly operations.



The self propelled part of conventional wheelchair was removed and replaced by smart features. The

joystick operative mode was replaced by touch mode wherein user can navigate by giving touch inputs

to a smart phone.

The wheelchair consists of gesture based movement which counters various forms of paralysis or if the

patient is unable to control the chair with fingers.

The third mode is voice incorporated for patients who are physically disabled or have musculoskeletal

problems.

For patients who are blind or have neurological issues, computer controlled mode is available wherein

a host computer monitors all the movement of chair. The location of chair with visuals is obtained

through smart phone/camera mounted on chair. Also if patient falls ill suddenly while travelling; the

location of patient along with his position is sent through GSM to emergency smart phone and PC

mode can be enabled just by pairing up with the required id and patient can be taken to a safe place.

Unlike all wheelchair products in market, this wheelchair does not just travels on flat, rough or slopes.

It has reliable mechanism to climb/de-climb stairs without any effort by user or external human. This

wheelchair is robust enough to carry the user through urban as well as rural pathways overcoming all

types of obstacles.

The wheelchair consists of three modifiable positions which includes chair position, bed position &

relax position. The bed position helps the patient‟s burden to be reduced while being shifted from

wheelchair to bed while sleeping; or in case there is bed shortage at paraplegic centre‟s. The chair

position is the conventional position while relax position is for user‟s comfort to read books, watch TV,

etc. A timely medication reminder facility is also made available for patient‟s personal health care.

The smart phone technology has significantly affected the lives of human and hence this technology

has been implemented as an integral part of this wheelchair as smart phones are available with at least 4.77

billion members across the globe. Smart features have been included to counteract various difficulties faced by a

conventional wheelchair user. Overall this wheelchair system can prove to be beneficial for all grades of people

in all fields relating to military, hospitals, paraplegic centre‟s or even domestically or during disastrous

situations like earthquake thereby making a patient totally self-reliant and self-dependent with high reliability,

comfort, care, assistance & optimal low cost.

II. Proposed Methodology 2.1 HARDWARE DESCRIPTION

The basic structure of our project consists of microcontroller, motor driver, smart phone, PC/Laptop,

power supply and motors. The main aim of this project is construction of wheelchair having a direction

control through voice commands, touches or hand gesture.

The touchpad comprises a smart phone. When pressure is applied to the capacitive screen of smart

phone, an XY co-ordinate location is produced and transmitted with Bluetooth available on smart

phone to Bluetooth module (HC-05) available on wheelchair and the wheelchair will move in the

desired direction.

A change in location of the pressure will result in a corresponding change in direction .The touchpad

also has a neutral or no movement point which will ensure efficient braking. This is very helpful for

paralyzed and physically challenged people.

Similarly, voice commands can be used as input to a decoder which converts a particular frequency of

voice into digital bits for controller to process it and take desired action. Using voice operative mode

the user can operate the wheelchair using pre-decided voice commands. The voice commands will be

transmitted via Bluetooth available on smart phones.

In hand gesture mode the user will be able to manipulate the wheelchair using hand movements. This is

achieved by using accelerometer sensor available on smart phone which are used for gesture gaming.

The data, as above, will be transmitted via Bluetooth. In automatic mode, the wheelchair is controlled

by a host PC to traverse the route. This is very helpful to navigate in places such as home or where user

is fully paralyzed. This feature can also be efficiently used if the patient feels ill and cannot regulate the

wheelchair himself/herself. The patient will thereby be leaded to his/her home or paraplegic centre

safely.



Fig.1. Main Block Diagram

Fig.4. Hardware Schematic

Fig.2.Simplified Schematic of PC mode Fig.3.Simplified Schematic of touch/gesture mode



2.2 MECHANICAL DESCRIPTION

The Shrimp rover is highly suitable for planetary exploration missions because of its unconventional

wheel order, in-built passive adaptability and good ability to climb obstacles. It is a spatial multi-body system

and a multi-variable, multi-parameter coupled non-linear system. Thus, kinematic and dynamic analyses for

such systems are complex and time consuming. We propose the use of RecurDyn, multi-body dynamics analysis

software. Compared to other such softwares, it overcomes shortcomings like excessive simplification, low

solving efficiency and bad solving stability. A potential application of this software in realistic modeling and

dynamic simulation of the Shrimp rover is presented. Simulation results obtained from RecurDyn have been

used to analyze the rover capabilities and select the actuators for the rover design. Simulation results are also

validated experimentally. Thus, it is observed that an accurate and a reasonably fast simulation tool like

RecurDyn has great potential in the field of space robotics.

Fig.5. Mechanical Design (a) Chair dimension (b) Centre bogie (c) Rear fork (d) Front fork

(a) (b)

(c) (d)



2.2.1 CURVED SURFACE ADAPTABILITY

It is very important for the rover to adapt passively to concave and convex surfaces as the

actual surfaces are not going to be flat in nature. For testing this ability, the rover was made to fall from a certain

height on concave and convex surfaces. It can be deduced that the parallel architecture of the bogies and the

spring suspended fork provides a non-hyperstatic configuration allowing the bogie to adapt passively to

any terrain profile.

2.3 ELECTRICAL SPECIFICATIONS

2.3.1 RHINO CONTROL BOARD

6V-25V input supply range.

On Board Regulator with filters

2 General purpose LED's

Power on/off toggle switch 10A

16MHz crystal for maximum speed

Onboard LCD connector compatible to HD44780 LCD

Modules

4 DC/2 Stepper motor 5A driving capability (Normal

configuration offers capability of 2 DC/1 Stepper motors)

PWM pins connected to motor drivers for speed control

of motors for two motor drivers

8ADC/Standard servo compatible connectors. 4 Servo connectors extra.

Onboard 36 kHz receiver to receive signals from RC5

remote.

2.3.2 BLUETOOTH MODULE

Supports master and slave modes.

Serial communication: 9600-115200bps.

SPP support

Support UART, USB, and PCM interface through host

system.

Easy configuration through AT commands.

Frequency-2.4-2.524 GHz.

Bluetooth core V2.0 compliant.

Fig.8. Rhino control board

Fig.9. Bluetooth module



Build in chip antenna.

Power supply 3.7-5

2.3.3 MOTOR DRIVER

Board size 45mm-31mm

L298 based design

Simple 8 pin interface PWM mode

Controls 2 phase bipolar stepper motor

Operates up to 18V DC

PWM operations up to 20KHz

Onboard 5V supply

2.3.4 RF 2.4GHZ USB LINK

Standard serial communication.

Socket for easy integration

Fast 250kbps RF air data rate to the end node

2.4 GHz for worldwide deployment

Up to 100 meters range.

2.3.5 RF 2.4GHZ SERIAL LINK

Standard serial communication.

Socket for easy integration

Fast 250kbps RF air data rate to the end node

2.4 GHz for worldwide deployment

Up to 100 meters range.

2.3.6 RS 37 DC GEARED MOTOR

Shaft diameter-6mm with internal hole

Shaft length 15mm

Weight 350gms

Torque-7 Kgcm-30Kgcm

Voltage 9-18V

III. Operating Principle 3.1 SURFACE CAPACITIVE TOUCH SCREEN

Capacitive touch panels offer outstanding accuracy, optics durability and touch accuracy. Slim border

design allows better integration for new generation flat panel displays. With excellent optical transmission, low

reflection, and minimized color distortion. The capacitive touch panel consists of multilayer coatings on a glass

panel. Transparent conductive coatings are coated on both sides of the glass panel. Specially designed electrodes

are laid around the panel‟s edge on top of the front-side conductive coating to evenly distribute a low voltage

across the front side conductive coating, creating a uniform electric field. The backside conductive coating is

used for electromagnetic interference (EMI) shielding. A hard coat layer is laid on top of the front-side

conductive coating to provide protection to the front-side conductive coating. The touch screen coated material

that stores electrical charges, when touched allows a small amount of charge to be drawn to the point of contact.

Circuits located at each corner of the panel measure the charge and send the information to the controller for

Fig.10.L298N driver

Fig.11. RF transmitter

Fig.13. DC motor

Fig.12.RF receiver



processing. Capacitive touch screen panels must be touched with a finger unlike resistive and surface wave

panels that can use fingers and stylus.

Fig.14. Layered structure of touch screen

3.2 ACCELEROMETER

Newton's second law of motion relates force, mass, and acceleration through this very simple equation:

Force = mass x acceleration (F = mxa)

or

a = F / m

This equation is the theory behind accelerometers: they measure acceleration not by calculating how

speed changes over time but by measuring force.

The accelerometers found inside smart phones clearly don't have gigantic masses bouncing up and

down on spring. Instead, smart phone accelerometers are based on tiny microchips with all their components

chemically etched onto the surface of a piece of silicon.

Fig.15. Structure of accelerometer

1. From the figure 15, right in the middle, there is an electrode (blue) that has enough mass to move up

and down very slightly when movement or tilt is produced.

2. The electrode is supported by a tiny beam (cantilever) that's rigid enough to hold it but flexible enough

to allow it to move.

3. There's an electrical connection from the cantilever and electrode to the outside of the chip so it can be

wired into a circuit.

4. Below the electrode, and separated from it by an air gap, there's a second electrode (green). The air gap

between the two electrodes means the blue and green electrodes work together as a capacitor. As we

move the accelerometer and the blue electrode moves up and down, the distance between the blue and

green electrodes changes, and so does the capacitance between them.

5. The electrodes are connected to more electrical terminals at the edges of the chip, again, so it can be

wired to a bigger circuit to note the readings.

http://www.explainthatstuff.com/integratedcircuits.html



3.3 DUAL TONE MULTIPLE FREQUENCY

When we press the buttons on the keypad, a connection is made that generates two tones at the same

time. A "Row" tone and a "Column" tone. These two tones identify the key we pressed to any equipment we are

controlling. If the keypad is on our phone, the telephone company's "Central Office" equipment knows what

numbers we are dialing by these tones, and will switch our call accordingly. If we are using a DTMF keypad to

remotely control equipment, the tones can identify what unit we want to control, as well as which unique

function we want it to perform.

Fig.16. DTMF keypad and related frequencies

IV. Experimental Result 1. According to the structural design and mechanism the wheelchair is able to climb stairs and trespass

small obstacles like stone, pot holes etc. easily. As per the height adjustment mechanism, user should

be able to adjust height manually whenever it is required.

2. In touch mode when an input is given from a smart phone, the Bluetooth module available on

wheelchair will receive the input and the wheelchair will move in the desired direction. A change in

location of the pressure will result in a corresponding change in direction .The touchpad also has a

neutral or no movement point which will ensure efficient braking. This is very helpful for paralysed

and physically challenged people.

3. In personal computer/laptop mode, inputs are given from PC through an application installed on a

computer. The receiver attached to the wheelchair will receive the inputs and the chair will move in the

desired direction. If „w‟ or 8 on keyboard is pressed then wheelchair will move forward, if „6‟ or „d‟ is

pressed then wheelchair will move right, if „4‟ or „a‟ is pressed then wheelchair will move left, if „2‟ or

„s‟ is pressed then wheelchair will move backwards, if „s‟ or „5‟ is pressed then wheelchair will stop.

Also it can be controlled with the help of mouse movement in the desired direction. This feature will

help efficiently if the patient feels ill and cannot regulate the wheelchair himself/herself. The patient

will thereby be leaded to his/her home or paraplegic centre safely by monitoring in-charge.

4. In gesture mode when an input is given from a smart phone, the Bluetooth module available on

wheelchair will receive the input and the wheelchair will move in the desired direction. When phone is

tilted forward the wheelchair will move forward, if left tilt is given the wheelchair will move left and so

on.

5. Similarly, voice commands will be used as input to a decoder (DTMF) which converts a particular

frequency of voice into digital bits for controller to process it and take desired action. Using voice

operative mode the user will be able to operate the wheelchair using pre-decided voice commands. The

voice commands will be transmitted via Bluetooth available on smart phones.



Fig.17. Implemented prototype of wheelchair

Fig.18. Flowchart



V. Conclusion This innovative project will come in handy for various people around the world who can‟t walk or are

partially handicapped & are blind. The design structured for this wheelchair is a comfortable one where the

patient will have no issues with comfort. Overall this wheelchair has the ability to travel anywhere with no

human efforts except giving it direction controls. It operates on battery which can be recharged. We have

described the system which is driven by the latest up growing technologies and advanced algorithms. Though

main focus is on human-machine system interface, further advancements can be done through more research.

The interface and software can be modified and re-developed according to the need in future. Further

advancement in the wheelchair are possible by decreasing the power requirements of the wheel chair or finding

a way to automatically charge the battery with the help of motion of the wheel chair or solar panel.

Acknowledgement We would like to extend our sincere & heartfelt obligation towards Mr. Bendre (Owner of Bendre

Fabrications), Mrs. R.S. Kamathe (HOD & Assistant Professor, PES MCOE), Mrs. A.P. Laturkar (Assistant

professor, project coordinator & guide, PES MCOE) and Mrs. M.S. Kanitkar (Assistant professor & project

coordinator, PES MCOE) of Electronics & Telecommunication department for their active guidance, help,

cooperation & encouragement. We would also like to thank Mr. D. T. Sharma and Mrs. K. Sharma for their

constant and precious help and support towards the accomplishment of the project.

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International Journal of Power Systems and Integrated Circuits, vol. 1, Special Issue, pp 48-51, December 2011.

[2] Manuel Mazo, Francisco J. Rodriguez, Jose L, Lazaro, Jesus Urena, Juan C. Garcia, Enrique Santiso, Pedro Revenga and J. Jesus

Garcia, “Wheelchair for Physically Disabled People with Voice, Ultrasonic and Infrared Sensor Control “, Autonomous Robots, vol.2, no. 3, pp. 203-224 ,Sep 1995.

[3] Ali Meghdari, F. Amiri, A. Baghani, H. Mahboubi, A. Lotfi, Y. Khalighi, R. Karimi, H. Nejat, M. Amirian, S. Kamali, and S.

Moradi, ”CEDRA”, July 2003,RoboCup Rescue Robot League Competition Awardee Paper. [4] Sandeep H.Deshmukh,Devesh Yadav & Binni Chowalloor,”Development of stair climbing transporter”, December 12-13 2007,13th

National Conference on Mechanisms and Machines (NaCoMM07).

[5] Ritika Pahuja, Narender Kumar,”Android Mobile Phone Controlled Bluetooth Robot using 8051 Microcontroller”, July 2014, Volume 2 Issue 7, International Journal of Scientific Engineering and Research (IJSER).

[6] Tabasum Shaikh, Naseem Farheen Sayyed, Shaheen Pathan, “Review of Multilevel Controlled Wheelchair”, 4th National

Conference On Electronic Technologies, pp. 275-279, April 2013. [7] Chandika T.Mohanraj, “Automation and Emerging Technology Development of 2d Seed Sowing Robo”, Journal of Agricultural

Science, vol. 1, no.1, June 2009.

[8] Vasundhara G. Posugade, Komal K. Shedge, Chaitali S. Tikhe, “Touch-Screen Based Wheelchair System”, International Journal of Engineering Research and Applications ,vol. 2, issue 2, pp.1245-1248 , Mar-Apr 2012.

Documents

Smart Mutatable Advanced Technology Wheelchair · Simulation results obtained from RecurDyn have been used to analyze the rover capabilities and select the actuators for the rover